Touch panel and manufacturing method thereof

ABSTRACT

Disclosed is a touch panel. The touch panel includes a plurality of sensing electrode patterns spaced apart from each other on a substrate; and a bridge electrically connecting the sensing electrode patterns to each other, wherein an end portion of the bridge is perpendicular to a surface of the substrate or is inclined within a predetermined angle with respect to a perpendicular line of the surface of the substrate.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a Continuation Application of prior U.S. patent application Ser. No. 14/428,090 filed Mar. 13, 2015, which is a U.S. National Stage Application under 35 U.S.C. § 371 of PCT Application No. PCT/KR2013/005911, filed Jul. 3, 2013, which claims priority to Korean Patent Application No. 10-2012-0108094, filed Sep. 27, 2012, whose entire disclosures are hereby incorporated by reference.

TECHNICAL FIELD

The embodiment relates to a touch panel. More particularly, the embodiment relates to a touch panel having improved visibility.

BACKGROUND ART

A touch panel including an input unit (pointing device) has been extensively used in displays of electronic devices such as personal digital assistants (PDA), a notebook computer, office automation (OA) device, a medical device, or an automobile navigation system. For example, a capacitive type touch panel is generally known in the art as well as a resistive type touch panel, an electromagnetic induction type touch panel, and an optical type touch panel.

In general, the capacitive type touch panel is classified into an analog type and a digital type.

Since the analog type touch panel includes a sheet type sensor electrode, a pattern is not required on a sensing region. However, the digital type touch panel requires a pattern for a sensor electrode in the sensing region. The digital type capacitive touch panel induces a current to confirm a touch location based on variation in capacitance caused by electrostatics of a human body and a transparent electrode. For example, in order to detect a location in the touch panel touched by a finger or a stylus, various technologies for the capacitive type touch panel have been developed.

For example, a lattice touch-sensing system for detecting a position of a touch on a touch-sensitive surface is disclosed in U.S. Pat. No. 6,970,160. The lattice touch-sensing system may include two capacitive sensing layers separated by an insulating material where each layer consists of substantially parallel conducting elements, and the conducting elements of the two sensing layers are substantially orthogonal to each other. Each element may be prepared as a series of diamond shaped patches that are connected together with narrow conductive rectangular strips. Each conducting element of a given sensing layer is electrically connected at one or both end portions thereof to a lead line of a corresponding set of lead lines. A control circuit may also be included to provide an excitation signal to both sets of conducting elements through the corresponding sets of lead lines to receive sensing signals generated by sensor elements when a touch on the surface occurs, and to determine a position of the touch based on the position of the affected bars in each layer.

The capacitive type touch panel generally includes two capacitive sensing layers. The two capacitive sensing layers are spaced apart from each other while interposing an insulation material therebetween in order to generate a capacitive effect between the two layers. Such a structure significantly increases a thickness of a structure of a panel which results in adversary effect on the miniaturization. Further, the capacitive type touch panel according to the related art includes a substrate on both surfaces thereof on which the two capacitive sensing layers are formed, respectively. Therefore, through holes must be formed in the substrate to serve as vias and circuit layering must be adopted in order to suitably connect conductor elements of the sensing layers to each other. Thus, the manufacture of the capacitive type touch panel may become difficult and complicated.

Accordingly, in order to solve the above problem, a scheme of reducing two capacitive sensing layers to one capacitive sensing layer has been used. Recently, a scheme of configuring sensing layers (sensing electrode pattern layer) as one layer and connecting the sensing layers to each other through a metal bridge has been used.

FIGS. 1 and 2 are sectional views illustrating a touch panel according to the related art, which shows a section of a metal bridge of the touch panel for connecting the sensing layers (sensing electrode layers) to each other.

The touch panel according to the related art will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, a metallic or non-metallic material 140 for forming a metal bridge is formed on a transparent window 110, and a photoresist 155 is formed on the metallic or non-metallic material 140 to etch the metallic or non-metallic material 140.

Next, as shown in FIG. 2, the metal bridge 150 is formed through an etch process.

In this manner, if the metallic or non-metallic material 140 is etched, since the end portion of the metal bridge 150 generally has no vertical structure, the metal bridge 150 has a trapezoidal shape, a reversed trapezoidal shape, a concave shape, or a convex shape. The above shape may be caused due to under cut when the material 140 has a single layered structure and due to a difference in etching rate between metals forming respective layers when the material 140 has a multi-layered structure.

According to the related art, since step difference L occurs in an end portion of the metal bridge 150 so that an angle between the end portion of the metal bridge 150 and a transparent window reaches at least 70°, external light is reflected by the metal bridge 150 so that the visibility of the touch panel is degraded.

DISCLOSURE Technical Problem

The embodiment provides a touch panel, in which an end portion of a metal bridge electrically connecting sensing electrode patterns to each other is perpendicular to a surface of a substrate or inclined within a predetermined angle with respect to a perpendicular line of the surface of the substrate so that external light is not reflected from the end portion of the metal bridge, thereby improving the visibility of the touch panel.

Technical Solution

According to the embodiment, there is provided a touch panel including: a plurality of sensing electrode patterns spaced apart from each other on a substrate; and a bridge electrically connecting the sensing electrode patterns to each other, wherein an end portion of the bridge is perpendicular to a surface of the substrate or is inclined within a predetermined angle with respect to a perpendicular line of the surface of the substrate.

According to another embodiment, the bridge may include a first end portion inclined at a first angle with respect to the surface of the substrate, and a second end portion inclined at a second angle with respect to the surface of the substrate.

According to another embodiment, a ratio of a length of a first surface facing the substrate to a length of a second surface opposite to the first surface in the bridge may be in a range of about 1:1 to about 1:1.2.

According to another embodiment, the predetermined angle may be in a range of about 0° to about 35°.

According to another embodiment, the bridge may include a plurality of metal layers.

According to another embodiment, the metal layers may include an electrode layer and a light absorption layer.

According to another embodiment, the bridge may be formed on one surface of the substrate, and the sensing electrode patterns are formed on a top surface of the bridge.

According to another embodiment, the sensing electrode patterns may be formed on one surface of the substrate, and the bridge is formed on top surfaces of the sensing electrode patterns.

According to another embodiment, a top surface of the bridge based on the substrate has a circular shape, an elliptical shape or line shape.

According to the embodiment, there is provided a method of manufacturing a touch panel, the method including: preparing a substrate; coating photoresist layers on the substrate at a predetermined interval; coating metal layers on top surfaces of the photoresist layers and between the photoresist layers, respectively; and forming a bridge by removing the photoresist layers.

According to another embodiment, an end portion of the bridge may be perpendicular to a surface of the substrate or be inclined within a predetermined angle with respect to a vertical line of the surface of the substrate.

According to another embodiment, the predetermined angle may be in a range of about 0° to about 35°.

According to another embodiment, the method may further include forming a plurality of sensing electrode patterns spaced apart from each other on the substrate after the preparing of the substrate, wherein the bridge is formed on top surfaces of the sensing electrode patterns.

According to another embodiment, the method may further include forming a plurality of sensing electrode patterns on a top surface of the bridge after the forming of the bridge.

Advantageous Effects

According to the embodiment, an end portion of a metal bridge electrically connecting sensing electrode patterns to each other is perpendicular to a surface of a substrate or inclined within a predetermined angle with respect to a perpendicular line of the surface of the substrate so that external light is not reflected from the end portion of the metal bridge, thereby improving the visibility of the touch panel.

DESCRIPTION OF DRAWINGS

FIGS. 1 and 2 are sectional views illustrating a touch panel according to the related art.

FIGS. 3 to 9 are sectional views illustrating a touch panel according to an embodiment.

FIG. 10 is a sectional view illustrating a touch panel according to the embodiment.

FIG. 11 is a sectional view illustrating a touch panel according to another embodiment.

FIGS. 12 to 14 are top views illustrating a touch panel according to still another embodiment.

MODE FOR INVENTION

Hereinafter, a touch panel according to the exemplary embodiment will be described in detail with reference to accompanying drawings. In a description of the embodiment, if the function or the structure related to the disclosure and generally known to those skilled in the art make the subject matter of the disclosure unclear, the details of the function or the structure will be omitted. The size of the elements shown in the drawings may be exaggerated for the purpose of explanation and may not utterly reflect the actual size.

FIGS. 3 to 9 are sectional views illustrating a touch panel according to an embodiment.

The touch panel according to the embodiment will be described with reference to FIGS. 3 to 9.

According to the embodiment, as shown in FIG. 3, a photoresist 220 is formed on a substrate 210, and a metallic material layer 230 is formed by coating a metallic material. In this case, the metallic material layer 230 may be formed in a single layer or a multi-layer using a plurality of materials. Meanwhile, the substrate 210 may include one of PET (polyethylene terephthalate resin), PC (polycarbonate), PMMA (polymethyl methacrylate), TAC (triacetate cellulose), glass and PES (polyether sulfone).

Next, a bridge is formed as illustrated in FIG. 4 by removing the photoresist 220. The bridge may include a metal bridge 235. In this case, when the metallic material layer 230 is configured in the multi-layer, as shown in FIG. 5, the metal bridge 235 is configured by a plurality of metal layers. For example, when the metal bridge 235 is formed in three layers, as shown in FIG. 5, a first metal layer, a second metal layer, and a third metal layer of the metal bridge 235 may serve as a light absorption layer 231, an electrode layer 232, and a light absorption layer 233, respectively.

As shown in FIGS. 3 to 5, if the metal bridge is formed by forming and removing the photoresist 220, an end portion of the metal bridge 235 is formed substantially perpendicular to a surface of the substrate 210.

That is, as shown in FIG. 6, the end portion of the metal bridge 235 is perpendicular to the surface of the substrate 210 or is inclined at a predetermined angle θ approximately perpendicular to the surface of the substrate 210.

For example, as shown in FIGS. 6 to 8, the end portion of the metal bridge 235 is inclined at a predetermined angle θ with respect to a perpendicular line of the surface of the substrate 210.

In this case, the metal bridge 235 is inclined at an angle being the range of 0° to 35°. When the inclined angle of the metal bridge 235 is beyond the angle range, external light is reflected by the end portion of the metal bridge 235 so that the metal bridge is visually recognized at a user' eyes. When the inclined angle of the metal bridge 235 is included within the angle range, external light is not reflected by an end portion of the metal bridge 235 so that the visibility of the touch panel is improved.

If the angle is less than 0°, it may occur reflection at the end portion of the metal bridge 235. If the angle is exceed 35°, sensing electrode patterns may crumble.

Further, according to another embodiment, the ratio of the length of a first surface to the length of a second surface on the metal bridge 235 may be within a predetermined range.

That is, as shown in FIG. 7, if a surface of the metal bridge 235 facing a substrate 210 is defined as a first surface and a surface opposite to the first surface is defined as a second surface, the ratio of the length L1 of the first surface to the length L2 of the second surface may be in the range of 1:1 to 1:1.2. In this manner, if the ratio of the length L1 of the first surface to the length L2 of the second surface is within the constant range, the end portion of the metal bridge 235 is approximately perpendicular to the surface of the substrate 210 so that the metal bridge 235 does not reflect external light.

In addition, since a plurality of metallic materials have different etch rates when the metal bridge 235 is formed in a multi-layer using the metallic materials, as illustrated in FIG. 8 or 9, the end portion of the metal bridge 235 is inclined at different angles θ with respect to the surface of the substrate 210. In this case, the angle θ has the range of 0° to 35°.

That is, the end portion of the metal bridge 235 may include a first end portion 236 inclined at a first angle and a second end portion 237 inclined at a second angle.

In this manner, if the first end portion 236 and the second end portion 237 are perpendicular to the surface of the substrate 210 or are inclined at a predetermined angle with respect to the perpendicular line of the surface of the substrate 210, the metal bridge 235 does not reflect external light.

FIG. 10 is a sectional view illustrating a touch panel according to the embodiment.

According to the embodiment, as shown in FIG. 10, after the metal bridge 235 and a first sensing electrode pattern 250 have been formed, an insulator 240 and a second sensing electrode pattern 260 are formed on the metal bridge 235, so that the touch panel is manufactured.

Meanwhile, the first and second sensing electrode patterns 250 and 260 include one of an ITO (Indium Tin Oxide), an IZO (Indium Zinc Oxide), a ZnO (Zinc Oxide), a CNT (carbon nano tube), an Ag Nano wire, and a conductive polymer, and a graphene.

FIG. 11 is a sectional view illustrating a touch panel according to another embodiment. FIG. 11 illustrates an example of a touch panel configured by forming a sensing electrode pattern on a substrate and forming a metal bridge on the sensing electrode pattern.

As shown in FIG. 11, in the touch panel according to another embodiment, sensing electrode patterns 250 and 260 are formed on a substrate 210 and an insulator 240 is formed on the sensing electrode patterns 250 and 260.

A metal bridge 235 is formed on the insulator 240. In this case, an end portion of the metal bridge 235 is perpendicular to a surface of the substrate 210 or is inclined at a predetermined angle θ with respect to the perpendicular line of the substrate 210.

FIGS. 12 to 14 are top views illustrating a touch panel according to still another embodiment.

According to still another embodiment, when viewing the touch panel from the top, even if the metal bridge 235 is configured in a bar shape as shown in FIG. 12 or a hollow elliptical shape as shown in FIG. 13, or in line shape facing each other as shown in FIG. 14, the end portion of the metal bridge 235 may be perpendicular to a surface of the substrate or is inclined within a predetermined angle with respect to a perpendicular line of the substrate.

As shown in FIGS. 12 to 14, if the metal bridge 235 of the touch panel is perpendicular to the substrate or is inclined within a predetermined angle with respect to a perpendicular line of the substrate, external light is not reflected by the end portion of the metal bridge 235 so that the visibility of the touch panel can be improved.

Hereinafter, a method of manufacturing a touch panel according to the embodiment will be described with reference to FIGS. 3 and 4. A description of a method of manufacturing a touch panel is basically incorporated with the description of this touch panel.

The method of manufacturing a touch panel according to the embodiment includes preparing a substrate; coating photoresist layers on the substrate at a predetermined interval; coating metal layers on top surfaces of the photoresist layers and between the photoresist layers, respectively; and forming a metal bridge by removing the photoresist layers.

The photoresist layers are removed from the substrate by exposure, development, and etch processes. As the photoresist layers are removed, only the metal layers coated between the photoresist layers may remain so that the metal bridge is finally formed.

In this case, the end portion of the metal bridge is perpendicular to the surface of the substrate or is inclined within a predetermined angle with respect to a perpendicular line of the substrate. Preferably, the predetermined angle may be in the range of about 0° to about 35°.

Further, after the preparing the substrate, the method of manufacturing a touch panel may further include forming a plurality of sensing electrode patterns to be spaced apart from each other on the substrate. The metal bridge may be formed on top surfaces of the sensing electrode patterns.

In addition, in the another embodiment, after the forming the metal bridge, the method of manufacturing a touch panel may further include forming the sensing electrode patterns on the top surface of the metal bridge.

A touch panel manufactured by the method of manufacturing a touch panel may include a metal bridge having an end portion perpendicular to the substrate or inclined at a predetermined angle with respect to the substrate. Accordingly, since external light is not reflected by the end portion of the metal bridge 235, the visibility of the touch panel can be improved.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

The invention claimed is:
 1. A touch panel comprising: a plurality of sensing electrodes spaced apart from each other on a substrate; and a bridge connecting one of the sensing electrodes to another one of the sensing electrodes, wherein the bridge includes at least two layers, wherein the bridge includes a bottom surface facing the substrate and a top surface opposite of the bottom surface, wherein at one end of the bridge, the bottom surface extend beyond the top surface by a prescribed protrusion length relative to an axis perpendicular to the surface of the substrate, and the prescribed protrusion length is smaller than the thickness of the bridge.
 2. The touch panel of claim 1, wherein the sensing electrodes include a plurality of first sensing electrode patterns and a plurality of second sensing electrode patterns, wherein the first sensing electrode patterns and the second sensing electrode patterns are insulated each other by an insulator, wherein the bridge connects one of second sensing electrode patterns to another one of the second sensing electrode patterns.
 3. The touch panel of claim 2, wherein a bottom surface of the first sensing electrode patterns and a bottom surface of the second sensing electrode patterns are provided on a same plane, and the bridge is provided over the insulator.
 4. The touch panel of claim 2, wherein a bottom surface of the second sensing electrode patterns and the bottom surface of the bridge are provided on a same plane, and the first sensing electrode patterns are provided over the insulator.
 5. The touch panel of claim 1, wherein at the end of the bridge, the angle between the axis perpendicular to the surface of the substrate and a virtual line extended from one end of the top surface to one end of the bottom surface is in a range greater than 0° and not greater than 35°.
 6. The touch panel of claim 5, further comprising a side surface extended from said one end of the top surface to said one end of the bottom surface, and the side surface has two angles of inclination relative to the axis perpendicular to the surface of the substrate.
 7. The touch panel of claim 6, further comprising another end of the bridge opposite of the one end of the bridge, and wherein one end of the bridge is provided on the one of the second sensing electrode patterns and the another end is provided on the another one of second sensing electrode patterns.
 8. The touch panel of claim 5, wherein a ratio of a length of the bottom surface of the bridge to a length of the top surface of the bridge is in a range of about 1.2:1 to about 1:1.
 9. The touch panel of claim 6, wherein the bridge comprises a first end portion inclined at a first angle relative to the axis perpendicular to the surface of the substrate, and a second end portion inclined at a second angle relative to the axis perpendicular to the surface of the substrate, and wherein the first angle and the second angle are in a range greater than 0° and not greater than 35°.
 10. The touch panel of claim 9, wherein the first end portion and the second end portion comprise a convex part.
 11. The touch panel of claim 9, wherein the first end portion and the second end portion comprise a concave part.
 12. A touch panel comprising: a plurality of sensing electrodes spaced apart from each other on a substrate; and a bridge connecting one of the sensing electrodes to another one of the sensing electrodes, wherein the bridge includes at least two layers, wherein the bridge includes a bottom surface facing the substrate and a top surface opposite of the bottom surface, wherein one end of the bridge includes a side surface formed from an end of the top surface to an end of the bottom surface, wherein the side surface has two angles of inclination relative to the axis perpendicular to the surface of the substrate.
 13. The touch panel of claim 12, wherein the plurality of sensing electrodes includes a plurality of first sensing electrode patterns and a plurality of second sensing electrode patterns, wherein the first sensing electrode patterns and the second sensing electrode patterns are insulated each other by an insulator, wherein the bridge connects one of the second sensing electrode patterns to another one of the second sensing electrode patterns.
 14. The touch panel of claim 13, wherein a bottom surface of the first sensing electrode patterns and a bottom surface of the second sensing electrode patterns are provided on a same plane, and wherein the bridge is provided over on the insulator.
 15. The touch panel of claim 13, wherein a bottom surface of the second sensing electrode patterns and the bottom surface of the bridge are provided on a same plane, and the first sensing electrode patterns are provided over the insulator.
 16. The touch panel of claim 12, wherein at the end of the bridge, the angle between the axis perpendicular to the surface of the substrate and a virtual line extended from one end of the top surface to one end of the bottom surface is in a range greater than 0° and not greater than 35°.
 17. The touch panel of claim 14, further comprising another end of the bridge opposing the one end of the bridge, and wherein both end of the bridges are disposed on the said two said second sensing electrode patterns.
 18. The touch panel of claim 15, wherein a ratio of a length of the bottom surface of the bridge to a length of the top surface of the bridge is in a range of about 1.2:1 to about 1:1.
 19. The touch panel of claim 16, wherein the bridge includes a first end portion inclined at a first angle relative to the axis perpendicular to the surface of the substrate, and a second end portion inclined at a second angle relative to the axis perpendicular to the surface of the substrate, and wherein the first angle and the second angle are in a range greater than 0° and not greater than 35°.
 20. The touch panel of claim 19, wherein the first end portion and the second end portion comprise a convex part.
 21. The touch panel of claim 19, wherein the first end portion and the second end portion comprise a concave part.
 22. The touch panel of claim 1, wherein the bridge and the sensing electrode patterns include different materials from each other.
 23. The touch panel of claim 22, wherein the bridge includes a metal, wherein the sensing electrode patterns include one of an ITO (Indium Tin Oxide), an IZO (Indium Zinc Oxide), a ZnO (Zinc Oxide), a CNT (carbon nano tube), an Ag Nano wire, and a conductive polymer, and a graphene.
 24. The touch panel of claim 1, wherein the substrate include one of PET (polyethylene terephthalate resin), PC (polycarbonate), PMMA (polymethyl methacrylate), TAC (triacetate cellulose), glass and PES (polyether sulfone). 